Working of electric vapor-lamps.



is well known.-

UNITED STATES PATENT QFFICE.

RICHARD KUOH, OF HANAU, GERMANY, ASSIGNOR TO THE FlRlvl OF W. G. HERAEUS, OF

' HANAU, GERMANY.

Specification of Letters Patent.

Patented April 7, 1908.

Applicatio'n filed December 7, 1905. Serial No. 290,799.

To ail whom it may concern:

. Be it knownthat I, RICHARD Kiion, a sub jcct of the German Emperor, and a resident of Hanan, Germany, have invented certain new anduseful Improvements in the VVorki-nfi of Electric Vapor-Lamps, of which the fa owing 1s a specification.

When the several known manners of producing electric light are compared with. regard to their efficiency, 11. e. the proportion etween their illuminating power and the spent energy, the gas or vapor electric lamps with mercur electrodes must be given a rdminent p ace among the other lamps, as The statements of the efficlency of the gas or vapor electric lamp vary between .35 and .8 watts per candle power.

It has been believed, that the eliiciency of such lamps is the most favorable for a certain low speclfic weight of the vapor in the lam Now that an increase in the specific weigfit corresponds to an increase of the fall of potentia in the column of light, it may besaid, that the efficiency of a gas or vapor electric lamp was the most favorable for a certain fall of potential in the column of light. An increase of the specific weight of the vapor or an increase of the fall of potential in such a lamp beyond a certain point was thought to debase" the efficiency. For instance in an article in the German periodical Centralblatt 1Z1 Elelctroteclm'ik 1902, number 23 von ecklinghausen says: Beyond 5 amperes the tension rises rapidly and the useful effect very soon becomes moderate. In the lamps to which this statement refers, the fall .'of potential in the column of light varied from .5 to 1 volt er centimeter of the length of the column of ight (wide .0. Schott, Zeitschm'ftfilr an ewamite Ohemie XVIII, 1905, page 618). 3 he fact, that with a further increase of the s ecific weight of the vapor the efficiency of the gas or vapor electric lamp with mercury electrodes was still further debased, has been proved by the as or vapor electric lam s o quartz-glass or scientific pur oses, w ich were recently placed on the mar st and in which the fall of otential was increased up to from 3 t0 4 v0 ts per-'centi" meter of the length of the column of light. The efiicieney was then reduced and the consumption of current was increased up to from 1 to 1.3 watts per candle power. For this reasonit hitherto assumed, that the consumption of electric energy would be further increased, if the specific weight of the vapor, in other words the electric potential of the lamp were to be increased, and therefore it was thought best not to go further, but to stick to the lowest possible specific weight of the vapor.

During my experiments I have discovered the startling fact, that on increasing theelectrio potential of the lamp far beyond the point hitherto tested an unex )ected change takes lace. The curve of e ciency of the lamp t ien changes its direction and the efficiency will quickly rise, so that its value will be far more favorable than the most favor able values hitherto attained for a low electric potential. The consumption of electric cprrent was reduced to .17 watts per candle power and no limit ap' ears to have been as yet reached in this rec uction. The electric potential of the'lamp was in this case increased u to about 25 or 30 volts or centi meter of t 1e length of the column 0 light; in other words it was so much multiplier as to. be about 25 to 30 times that potential, which was hitherto elnloyed for attainin the GillClG-IICY, which compensates for the debasement of the el'licicncy of the radiation of the luminescence and moreover it produces a very considerable improvement in the total efliciency. The described important observations rendered it possible to produce a mercury light, in which a hitherto unknown rofit is made-out of the electric current. It 18 only necessary, to increase the electric loadef the lamp and thereby to increase the specific weight of the vapor beyond that hitherto in use, until that point is attained, at which the curve of the efficiency changes its direction. The construction of the lamp differ from that hitherto in use. However .the stpecific construction of the lamp require for carrying out this new method is immaterial. The essential point is, that the parts of the lamp be capable of withstanding the high temperature, which is producedat the high electric load. I may lay stress upon the fact, that the gas or vapor electric'lamp can be now very much reduced in its length. For the ordinary falls of potential of from 110 to 220 volts the hitherto usual length of the column of light of from 50 to 200 centimeters can be reduced to a few centimeters, say from 6 to 15 centimeters.

In case the electric light is desired to be produced within liquids, be it for the purpose-of attaining certain chemical effects, or

e it for illuminating purposes, the illuminating tube of the lam Wlll require to be inclosed in a second tn )6 or vessel molten on it, so as to protect the illuminating tube from contact with the liquid.

What I claim as. my invention, and desire to secure by Letters Patent, is

1. The method of working gas or vapor electric lamps having mercury electrodes to increase their efliciency which consists in applying to said. electrodes an electric potential greater for unit length of column of light than that corresponding to the minimum point of its curve of efficiency, substantially as described.

2. .The method of working gas or vapor electric lamps having mercury electrodes which consists in applfying to said electrodes an electric potentia not less than twentyfive volts er centimeter of the length of col umn of lig it, substantially as described.

In testimony whereof I have signed my 40 name to this specification in the presence of two subscribing witnesses. RICHARD KUCTI.

Witnesses:

FRANZ I'IASSLACHER, MICHAEL VOLKE. 

